The present invention relates to the field of removal of photoresist and photoresist residue from semiconductor wafers. More particularly, the present invention relates to the field of removal of photoresist and photoresist residue from semiconductor wafers using supercritical carbon dioxide.
Manufacture of semiconductor devices requires application and subsequent removal of a photoresist chemical from a surface of a semiconductor wafer. The removal of the photoresist chemical, commonly known as stripping, may be immediately preceded by a plasma ashing, etching, or other semiconductor manufacturing step. These steps can degrade or carbonize the photoresist chemical and leave a photoresist residue that difficult to remove by current stripping methods. The current stripping methods require that the wafers be dipped into baths of commericially available chemical mixtures known as strippers. The baths may employ heat or ultrasonic augmentation. Typically, the baths employ immersion times of twenty to thirty minutes to achieve complete removal of photoresist or photoresist residue from the wafer surface.
What is needed is a more effective method of removing photoresist.
What is needed is a more effective method of removing photoresist residue.
What is needed is a more effective method of removing photoresist.
What is needed is a more effective method of removing photoresist residue.
The present invention is a method of removing a photoresist or a photoresist residue from a semicondutor substrate. The semiconductor substrate with the photoresist or the photoresist residue on a surface of the semiconductor substrate is placed within a pressure chamber. The pressure chamber is then pressurized. Supercritical carbon dioxide and a stripper chemical are introduced into the pressure chamber. The supercritical carbon dioxide and the stripper chemical are maintained in contact with the photoresist or the photoresist residue until the photoresist or the photoresist residue is removed from the semiconductor substrate. The pressure chamber is then flushed and vented.